Process and apparatus for smelting volatile ores



W. D. KILBOURN. PRocEss AND APPARATUS role sMELTlNG voLAmE oms.

APPLICATION FILED JULY 14,1917.

Patented N 0V. 16, 1920c 2 SHEETS-SHEET l.

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mw@ Qwgf WI D. KILBOURN. PROCESS AND APPARATUS 'Foa sMELTmG voLATlLE oPEs.

APPLICATION FILED JULY 14.191]- 1,358,856. PAtendNov. 16,1920.

2 SHEETS-SHEET 2. is wg Y wf- UNITED STATES PAIENir OFFICE.

WILLIAM D. KILBOURN, or PUEBLO, COLORADO, AssIGNOR To UNITED STATES sMELTING, RESINING an MINING COMPANY, A CORPORATION OF MAINE.

. PROCESS ",AND APPARATUS FOR SMELTING VOLATILE OBES.

To all whom. t may cof/wem:

Be it known 'that I, WILLIAM D. KIL- BOURN, a citizen "of the United States, resiolinfrA at Pueblo, yin the county of Pueblo and` tate of Colorado, have invented certain new and useful Improvements in Processes and Apparatus for Smelting Volatile Orcs, .and I do hereby declare'the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appere tains to make and use the same.

This invention relates to a process and apparatus for smelting volatile ores.

In the present process of smelting zinc ores, the ,ores are reduced in retorts or muilies, and the zinc vapor condensed to metal in suitable condensers. ,The zinc ores generally carry many metallic values, such as gold, silver, copper and lead, which collect in the fused ore remaining in the retort. This fused mass is removed from the retort and collected in a cooled, coarsely granular condition, and subsequently smelted in a blast furnace to recover its metallic values. The shaft-type blast furnace as suitable for smelting zinc ores, because zinc is reduced 'at a comparatively low temperature, and with the high pressure blast the temperatures are so high and the fusion of the ore so rapid that much of the zinc is collected with the otherv metals in the matte and bullion. Further, to smelt zinc ore, the column of ore shouldY be kept as low as possible in orderto properly reduce the zinc and' a high pressure blast will not traverse or heat such a low column charge with the uniformity requisite for the proper volatilization and removal of the zlnc. l

The primary object of the present invention is to provide a process of smelting zinc ores in a shaft-type blast furnace by which the zinc is effectively removed as zinc oxid.

In accordance with this object, one feature of the invention contemplates supportingo-a fluxed ore containing a reducing agent in a low column on a grate, directing an air blast from the sides through the column to reduce the ore and fuse the material at the bottom of the column, lcollecting the fused mass in a body immediately below the grate, holding the fused mass in'a molten.

I. Specification of Letters Patent.

heretofore constructed has not been\ 'bottom of the shaft.

Patented Nov. 16, 1920.

Application "filed July 14, 1917. Serial No. 180,598.

condition, and removing zinc oxid from the gases leaving the top of the furnace.

Another object of the invention is to provide an Improved shaft-type blast furnace 1n whlch ores containing volatile metals may be effectively and continuously smelted.

In accordance with this object, another feature of the invention contemplates the provIsIOn in a blast furnace of the shafttype, of a reducing chamber at the lower end of the shaft, a grate at the bottom of the reducing chamber, a crucible mounted below the grate, and a series of twyers mounted in the shaft near the base' of the reducing chamber and above the grate.

Other features of the invention consist in certain improved processes and blast furnace constructions for smelting volatile ores, the advantages of which will be obvious to those. skilled in the art from the following description. The various features of the invention are Illustrated in the accompanying drawings, iny which Figure 1 is a view in vertical section taken on the line 1 1 of Fig. 3, s how- Ing a shaft-type blastfurnace embodying the invention in its preferred form; Fig. 2 1s a vlew in vertical section of the furnace taken on the line 2 2 of Fig. 3; and Fig. 3 is a view in horizontal section of the furnace taken on the line of Fig. 2.

T he blast furnace illustrated in the drawings has a vertical shaft which has a height substantially equal to the width of the fur nace. The lower ortion of the shaft in which the Ore is re uced is surrounded by a rectangular water jacket 10 which is supported on Opposite sides upon horizontal water cooled girders 12. The girders 12 are supported at their ends upon water cooled girders 14, which, in turn, are su ported at their ends on columns 16. The siiaft has a substantially uniform area throughout its height and a water cooled grate 18 is mounted below the water jacket 10 and covers the The grate 18 is supported at its end upon the girders ,14, and a pair of water cooled rods 20', extending across the central portion of the shaft, support the grate against the weight Yof the column ofore. The upper portion 22 of the shaft consists of a refractory masonry construction which is supported upon the water jacket 10 and a series of beams 24. The beams 24 are supported at their ends upon columns 26 which rest upon the upper ends of the columns 16. A flue 28 for the volatilized metal fumes is connected with the portion 22 of the shaft and leads to a bag house or settling chamber. i flue 28, a door 3() isformed in the sectlon 22, through which the charge may be placed in the furnace. The upper end of the shaft is covered with a cover 32, which consists of mufile shapedrefractory forms supported at their opposite ends upon trucks 34: The trucks are mounted on tracks 36, which extend along the side of the furnace and -p ermit the cover to be moved from its posltion over the shaft to open the shaft for barring or inspection. If it is desired, the cover may be moved back from the top of the shaft to permit the shaft to be charged from a floor 38 directly through the top. Lateral air blast twyers 40 pass through thesldes and ends of the water jacket 10 immedlately above the grate 18, and are connected through valves 42 and pipes 44 with bustle mains 46.

To insure that the grate will be maintained open, so that the furnace will operate continuously, a water cooled crucible 48 is mounted directly below the grate 18 and has a refractory lining which will radiate the heat of the slag and prevent the fused mass from chilling on the grate. The crucible 48 collects the fused mass passing through the grate and holds it in a molten condition directly below the grate. A tap hole 50'is formed at the bottom of the crucible, by which the matte and bullion may be removed from the crucible, and a comparatively large tap hole 52 1s formed in the upper edge of the crucible by which the slag may be drawn off separately from the matte 'and bullion. The tap hole 52 is also arranged to be opened and closed so that a certain amount of the blast gases passing through the grate may escape therethrough if found desirable. The crucible 48 is mounted on a truck 54 by which a loaded crucible may be' removed from below the furnace and a new crucible substituted therefor.` In this way a body of slag, bullion and matte maybe conducted to any desired point before it is discharged.

To smelt' zinc ore in the Dfurnace illustrated in the drawings, a charge of ore which is thoroughly mixed with fluxes and a reducing agent such as coke is placed on the grate 18, in a column which preferably does not extend above the water jacket 10. An air blast is admitted at the bottom of the reduction chamberfrom the twyers 40 to raise the temperature and start the smelting operation'. The ltwyers are preferably directed downwardly toward the grate and have a blow-pipe action on the Opposite the coke to raise the temperature sufficiently high to fuse the ore immediately above the grate. A portion of the air from the twyers may pass down through the grate. The major part or all the air passes upwardly through the body of the ore. The greatest heat is produced immediately above the grate, which prevents slag on or near the grate from chilling, and the passage of the gas through the grate will tend to carry the slag through the grate with-it. As the smelting progresses, the heated gases which pass up through the ore, raise the temperature of the ore to reduce the zinc and burn the zinc to Zinc oxid. The zinc oxid is sucked off through the flue 28 along with the blast gases and passes into the bag house filter. The zinc is substantially removed from the ore by the time it has moved down in the shaft from the top of the column to the zone of the direct action of the twyers, and the ore does not-fuse until it passes into this Zone. As the charge of ore sinks in the shaft, new ore is passed in through the door 30 or top of-the furnace to maintain a substantiallyuniform height of column.`

Should the ore run high in zinc, it is desirable that the column of ore be low and the escape of gas below the grate be prevented or held at a minimum. In this way the top of the body of ore will be hot, to insure the reduction and burning of all the zinc. If, on the other hand, the ore contains a volatile vmetal such as silver it is desirable to have the top of the column of ore comparatively cool. To accomplish this the column of ore should be increased in height, and the opening of the tap hole 52 may be enlarged to permit the escape of heated blast gases below the grate.

The furnace primarily employs a low pressure air blast, and by varying the pressure of the blast and the direction of the movement of the heated gases, the heat `of the different zones in the shaft may be accurately regulated to obtain any desired result. The movement of the gases may he controlled by permitting an escape of gases below the grate through the tap hole 52, and by employing a damper effect to the passage of the gases up through the charge by varying the height of the charge. The heated gases passing throughthe grate may also heat the fused mass in the crucible and hold it in a fluid condition, or the heat of the crucible may be reflected and radiated up through the grate to assist in maintaining the gases in a heated condition so that theirv fused, the surface of the crucible may be raised close to the bottom of the grate to insure that the grate will not be clogged by the slag, and as the slag passes through the grate it may run out through a tap hole in the crucible and discharge into a collecting car or hopper.

7hile the above invention has been illustrated and described as a process and apparatus for treating zinc ores, the invention is not limited to the treatment of Zinc ores, but may be employed for the treatment of other kinds of volatile ores.

I claim- 1. A blast furnace for smelting volatile ores, having, in combination, a comparatively low shaft having a reducing chamber at its lower end, means for removing the volatilized metallic oXid from the upper end of the furnace, a grate at the bottom of the reducing chamber, means for directing a comparatively low pressure blast laterally into the reducing chamber above the grate, and a crucible supported immediately below the grate.

2. A blast furnace for smelting volatile ores, having, in combination, a comparatively low shaft having a reducing chamber at its lower end, means for removing the volatilized metallic oxid from the upper end of the furnace, a grate at the bottom of the reducing chamber, means for maintaining a heat radiating surface directly below the grate, and a series of twyers for directing an air blast laterally into the reducing chamber above the grate.

-3. A blast furnace of the shaft-type having, in combination, a shaft having a reducing chamber at its lower end, a grate at the bottom of the reducing chamber, a series of lateral twyers mounted in the' shaft above the grate, a heat radiating Crucible mounted below the grate and means for permitting a regulated iow of air down through the grate.

4. A blast furnace of the shaft-type having, in combination, a shaft having a reducing chamber in its lower portion, a grate at the bottom of the reducing chamber, a series of twyers in the shaft near the bottom of the reducing chamber and inclined downwardly toward the grate.

5. A blast furnace for. smelting volatile ores, having, in combination, a comparatively low shaft having a reducing chamber at its lower end, a grate at the bottom of the reducing chamber for supporting a comparatively low column of ore, means for directing an air blast laterally through the column of ore above the grate to fuse theV ore at the grate, and means for maintaining a heat radiating surface below the grate.

6. A blast furnace for smelting volatile ores, having, in combination, a shaft having a height approximately its width and having.

escape of volatile lmetal fumes, a grate at the bottom of the reducing chamber, twyers for directing an air blast laterally into the reducing chamber above the grate, and

` means for maintaining a heat radiating surface directly below the grate.

8. The process of smelting zinc ores in a shaft-type furnace comprising, supporting fluXed ore containing a reducing agent in a low column on a grate, directing 'an air blast through the ore from the sides of the column above the grate to reduce the ore and fuse the material of the column, collecting the fused mass in a body immediately below the grate, holding the fused mass in a molten condition, and removing zinc oxid from the gases leaving the top of the furnace.-

9. The process of smelting zinc ores in a shaft-type furnace comprising, supporting the ore in a low column on a grate at the trolling the pressure and circulation of the air blast to hold the fused mass in a molten condition.

'10. The process of continuously smelting' zinc ores in a shaft-type furnace comprising, supporting the ore in a low column on a grate at the bottom of the furnace shaft, directing a comparatively low pressure blast through the column to fuse the material at the bottom thereof, maintaining a reducing agent -in the column to be acted upon by the blast, collecting the fused mass in a'body 115 immediately below the grate, and controlling the height of the column and the passage of the gases downwardly through the grate to hold the fused mass in a molten condition.

11. The process of smelting zinc ores in a shaft-type furnace comprising, supporting fluXed ore in a low column on a grate at the bottom of the furnace, directing an air blast through the column to reduce' and 125 fuse the material, maintaining a heat radiating surface below the grate, and controlling the blast to keep the material immediately above the grate in fused condition 12. The process of smelting zinc ores containing metallic values such as gold, silver, copper and lead, in a shaft-type furnace, comprising supporting the iuxed o're in a column on a grate at the bottom of the furnace, directiv` an air blast through the ore from the sides of the column above the grate to fuse the ore and burn the zinc to zinc oxid, removing the zinc oxid at the top of the furnace withl the blast gases, collecting the fused mass in a body below the grate, and separating the slag from the metallic matte and bullion in the fused body.

13. The process of smelting zinc ores containing metallic values such as gold, silver, copper and lead, in a shaft-type furnace, comprising supporting the fluxed ore in a column on a grat-e at the bottom of the furnace, directing a low pressure air blast from the sides ofy the column above the grate to volatilize the zinc and fuse the ore collecting the fused ore in bodv below theA grate, controlling the passag of gas through the grate'and the height of\the column of\ ore to hold the fused ore in a molten state, and separating the slag from the metallic matte of the fused ore.

14. The processof smelting zinc ores comprising supporting fluXed ore in a comparatively low column, directing an air blast laterally through the sides of the column laterally through the sides of the column` near its hbase to fuse the material of the column below the zone of direct action of the blast, separating the fused material from the column as it is fused;y and controlling the passage of air up through the column to regulate the heat of the different zones in the column.

\, WILLIAM D. KILBOURN. 

